Not Applicable
Not Applicable
This invention relates to the field of diagnostic medical devices and in particular the manufacture of ear tips for use on a binaural stethoscope. The prior art in the field discloses a number of types of ear tips for use on a stethoscope or other similar devices. Ear tips are generally manufactured out of an elastomeric material so to provide enough flexibility in the shape and comfort during their use; less frequently ear tips are manufactured using a more rigid material providing more durability but decreased comfort. Regardless of the actual rigidity of the material used, the process of injection molding is the preferred method of forming a specific ear tip, whereby a material, such as PVC (polyvinylchloride), is injected into a forming mold where the material hardens to form the desired shape. Ear tips are generally comprised of two sections, where the first section houses a means of attachment to the binaural and the second section interfaces with the auditory canal of a user""s ear.
Ear tips disclosed in prior art teach the use of compression, whereas certain internal and outer diameters are held during the manufacture such that the required compression ratios are generated by the application of axial forces (U.S. Pat. Nos. 4,852,684, 4,913,259, 5,288,953). The compression ratios serve to allow for a degree of flexibility in the ear tip while being fit into the ear and further serves to provide for enough resistance so that the ear tip does not collapse. Though compressible ear tips provided some degree of comfort and provide for some conformity to individual ear shapes, due to the compressible nature of these ear tips they do not conform to the infinite variations of ear shapes, and do not provide for a wholly airtight seal when inserted into an ear.
Other art teaches the use of a foam earpiece capable of achieving slow compression rates as a method of achieving both comfort and a complete acoustic seal (U.S. Pat. No. 4,724,942).
This disclosed invention teaches a method for how to make use of an ear tip having a liquid gelatin, saline, gas, or other fluid inserted into a sealed airtight chamber with a true audio port for the passage of sound. The result of the gel chamber is that the ear tip will operate using principles of displacement within the sealed chamber that act to expand circumferentially throughout the linear cross section geometry, thereby forming a complete and continuous acoustic seal with the user""s outer auditory canal. This invention further teaches a manner in which a displaceable ear tip is attached to a soundtransmitting device such as a stethoscope. Finally the disclosed invention teaches a method of manufacturing such an ear tip.
The preferred embodiment of the disclosed invention comprises a liquid gelatin filled ear tip as a single, functional unit for coupling sound from the binaural to the user""s auditory canal through a center auditory passage, and which ear tip has a first section designed to interface with a listening device and a second section to interface with a human ear that encapsulates a sealed airtight chamber. The disclosed ear tip is manufactured from a soft elastomeric material, such as PVC or other thermoplastic or liquid injection molding material, such as silicone, but may be manufactured of any material offering elastomeric properties, to form a singular elastomeric form. The ear tip is formed so that there is a top section of a minimum wall thickness having a beveled portion on the external surface at the end of the top section, that when inverted mates with the bottom section and whereby the aforesaid minimum wall thickness forms the outer wall of the sealed chamber within the second section. The bottom section with walls of greater thickness provides for the center auditory passage, a means of attachment to a listening device and an indentation to receive the beveled edge, such that when the beveled edge is sealed to the indentation adhesive peel is eliminated. The one piece molded form is turned inside itself so as to create an outer wall and an inner wall, which inner wall also serves as the exterior wall of the center auditory passage; and whereby the exterior wall is of a great enough thickness preventing the compression or the collapse of the center auditory passage, and the outer wall is a minimum thickness such to allow sufficient flexibility and expansion of the sealed airtight chamber housed in the second section upon the exertion of external forces. After the top section of the molded form is inverted, the beveled edge of the top section mates with the molded recess of the bottom section and is sealed with an adhesive agent or other method used to create a seal. After the top section is sealed to the bottom section, a fluid is injected into the sealed airtight chamber formed by the outer wall and the inner wall, and the injection hole is subsequently sealed.
The fluid filled ear tips establish a maximum acoustic seal and provide for minimum discomfort associated with extensive use of the invention. The device is designed to displace and deform under standard radial loads associated with inserting the stethoscope ear tip into one""s ear canal, and where the center sound passage remains constant and unaffected by the flexing or expansion of the filled chamber thereby allowing sound to travel through the chamber unobstructed. The full expansion, that results from displacement within the chamber, of the disclosed invention within the user s ear canal creates a complete and continuous acoustic seal thereby significantly reducing the infiltration of ambient noise.
The present invention comprises a first section that houses a bullet point shaped receptacle within the ear tip that interfaces with a matching bullet point shaped distal end of a stethoscope. The second section provides for an airtight hollow chamber that encapsulates a liquid gelatin. As a result of the liquid gelatin chamber of the second section, the portion of the device interfacing with a user""s ear, the ear tip contours to the infinite variations of different individual""s ear canal shape by circumferentially filling in the linear variations within a user""s ear. Infinite variations are achieved under the principles of displacement, whereby the volume of the airtight cavity is fixed and does not change when pushed. Thus, when the disclosed ear tip is inserted into the ear, the high points within the ear push against the exterior of the second section and the ear tip pushes back because of displacement into the lower points thereby creating a complete seal with the ear. Therefore, the singular design for this ear tip provides for a custom fit to an infinite number of users. The device also provides for a true communication port with user""s ear canal.
Furthermore, in the preferred embodiment, the material used to fill the chamber is selected such that the material at normal body temperature of 98.6xc2x0 remains resistant such that the ear tip is solid enough to completely contour to all of the spaces and linear irregularities within a user""s ear canal. Furthermore, the material selected remains pliant when the ear tips are exposed to freezing temperatures, such that the ear tips do not crack under extreme temperatures.
In another preferred embodiment of the disclosed invention, the sealed airtight chamber is filled with a gaseous substance or matter such as nitrogen so as to be entirely displaceable.
In another preferred embodiment of the disclosed invention, the sealed airtight chamber is filled with saline so as to be entirely displaceable.
In another preferred embodiment of the disclosed invention, the sealed airtight chamber is filled with a foam material so as to be entirely displaceable.
In another preferred embodiment of the disclosed invention, the sealed airtight chamber of the ear tip is filled with any substance or combination of substances known in the field, such as silicone, oil or water, or other such substance not yet invented so as to be entirely displaceable.
In another preferred embodiment of this invention, the disclosed ear tip is impregnated with an anti-microbial agent. The inclusion of an anti-microbial agent into the ear tip reduces the number of times that the ear tips must be sterilized by allowing the ear tip to remain free from bacteria from the user""s ear, other users of the same stethoscope, or from patients being diagnosed.
In yet another embodiment, the disclosed ear tip is designed such that a bullet point receptacle, within the first section, secures the ear tip to the binaural of the stethoscope thereby preventing the ear tip from inadvertently disengaging from the ear tip binaural of the stethoscope. This is a particular concern with standard threaded ear tips frequently unscrewing from the user""s stethoscope binaural or disengaging from a standard stethoscope barb. This feature also allows the ear tip to be removed for cleaning without a concern for creating a substandard seal after the reattachment of the ear tip to the stethoscope, and thereby offering an ear tip with substantially improved durability, and which does not necessitate frequent replacement.